The greenhouse effect is the process that keeps the Earth warm enough for life.
It
begins when the Sun sends energy to Earth as shortwave radiation, such as visible
light and ultraviolet rays. Some of this energy is reflected back into space due to
albedo, which is the measure of how much sunlight a surface reflects. Bright
surfaces like ice and snow have a high albedo, meaning they reflect more sunlight,
while darker surfaces like forests and oceans have a low albedo, meaning they
absorb more sunlight. The energy absorbed by the Earth’s surface heats it up, and
the surface releases this energy as longwave infrared radiation back toward space.
However, not all this heat escapes. Greenhouse gases in the atmosphere, such as
carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O), absorb some of this
heat because of their molecular structure. These gases then re-emit the heat in all
directions, including back toward the Earth’s surface, warming the planet further.
This ability to trap heat also depends on emissivity, which is a measure of how
well a surface emits energy. Greenhouse gases have specific emissivity properties
that allow them to trap heat efficiently.
This natural process keeps Earth’s average temperature at around 15°C, making life
possible. Without the greenhouse effect, Earth would be much colder, with an
average temperature of about -18°C. However, human activities such as burning
fossil fuels, deforestation, and industrial emissions are increasing the levels of
greenhouse gases in the atmosphere. At the same time, the melting of ice reduces
Earth’s albedo, meaning more sunlight is absorbed instead of reflected. These
changes enhance the greenhouse effect, causing global warming, rising sea levels,
and extreme weather patterns.
In summary, the greenhouse effect is a delicate balance that regulates Earth’s
temperature, but human actions are tipping this balance, leading to serious
environmental challenges.

